1. Field of the Invention
This invention relates generally to a system and method for diagnosing fault conditions in a vehicle and, more particularly, to a system and method for capturing operating parameter data whenever a diagnostic trouble code (DTC) is triggered in a vehicle, and applying mathematical models to both the parameter data and the DTC data to diagnose the reason for the fault condition.
2. Discussion of the Related Art
Modern vehicles are complex electrical and mechanical systems that employ many components, devices, modules, sub-systems, etc. that pass operating information between and among each other using sophisticated algorithms and data buses. As with anything, these types of devices and algorithms are susceptible to errors, failures and faults that affect the operation of the vehicle. When such errors and faults occur, often the affected device or component will issue a fault code, such as a diagnostic trouble code (DTC), that is received by one or more system controller identifying the fault, or some ancillary fault with an integrated component. These DTCs can be analyzed by service technicians and engineers to identify problems and/or make system corrections and upgrades. However, given the complexity of vehicle systems, many DTCs and other signals could be triggered for many different reasons, which could make trouble-shooting particularly difficult.
As mentioned above, modern vehicles have a number of mechanical and electrical parts that are in electrical communication through various controllers. If a certain actuator, sensor or sub-system is not operating properly, the component or sub-system, or its controller, will typically provide a DTC that is received by a system controller, such that the DTC can be either downloaded using telematics services, such as OnStar™, or diagnostic devices during service of the vehicle. However, a DTC can be triggered for a variety of reasons and based on many different combinations of measured parameters. This often makes it difficult to diagnose the true root cause of a problem based on a DTC value alone. This can result in the inability to find or repeat a problem when the vehicle is being serviced, which leads to customer dissatisfaction, increased future warranty costs, and missed opportunities to improve system designs based on real-world failure modes.
Given the unacceptably high rate of missed diagnoses of vehicle faults using current techniques, there is a need to improve the fault diagnosis of vehicle systems by capturing more operating parameter data when a DTC is triggered and applying advanced mathematical techniques to that data to find the true root cause of any fault condition.